1. Field of the Invention
The present invention relates to a container for containing powders such as a washing powder and the like therein.
2. Discussion of Related Art
FIGS. 10 and 11 show a container disclosed in Utility Model Application 62-120,792 which has been filed by the present inventors. The container comprises a main body 1 having an approximately rectangular parallelepiped shape and having a rectangular shaped opening 2 at an upper portion thereof, and a lid member (not shown) for covering the opening 2 and the upper portion of the main body 1.
The main body 1, called the pillar-carton, comprises a blank sheet 3 for constructing four end walls and four side corners of the main body 1 and a frame member 4 for preventing the main body 1 from deformation.
The blank sheet 3 comprises a main sheet of paper materials and a coating layer of varnishes formed on one of the surfaces of the main sheet.
The frame member 4, which is made of synthetic resins such as polypropylene and the like, comprises a rectangular tray shaped lower portion or tray 5, including a bottom portion 5a having a rectangular shape, a pair of first side walls 5b of low height disposed at longitudinal edges of the bottom portion 5a and a pair of second side walls 5c of low height disposed at transverse edges thereof, a rectangular frame shaped upper portion or a frame 6 including a pair of longitudinal end walls 6a and a pair of transverse end walls 6b, and a pair of pillars 7 for connecting central portions of the second side walls 5c of the tray 5 to central portions of the transverse end walls 6b of the frame 6 so as to be assembled the upper portion just above the tray 5 at a predetermined interval as shown in FIG. 11. A peripheral projection 8 is formed outward peripherally at outer surfaces of the longitudinal and transverse end walls 6a and 6b of the frame 6. The peripheral projection 8 is a portion for engaging with a groove formed at an inner peripheral wall of the lid member when the main body 1 is covered with the lid member. Also, a pair of rivets 9 used for putting a handle member (not shown) to the main body 1 are disposed at portions beneath the peripheral projection 8 on the transverse end walls 6b. Each of the rivets 9 has a approximately T-shaped cross section and has a circular plate formed at a top portion thereof. In the frame member 4, a plan-view geometry of the bottom portion 5a of the tray 5 is not greater than that of the frame 6.
The frame member 4 is surrounded with the blank sheet 3 so as to cover a space defined by the tray 5 and the frame 6 and the pillars 7 therewith to thereby be assembled into the main body 1. Specifically, a pair of the transverse marginal portions of the coating layer of the blank sheet 3 are pasted up on one of the pillars 7 so that the marginal portions face each other. A pair of the longitudinal marginal portions of the coating layer of the blank sheet 3 are peripherally pasted up on the first and second side walls 5b and 5c of the tray 5 and on the longitudinal and transverse end walls 6a and 6b of the frame 6.
When the main body 1 is manufactured, the blank sheet 3 is pasted up on the side portion of the frame member 4 while the frame member 4 is molded by injection molding. In this case, the blank sheet 3 is put in a mold which can be separated into male and female sections, i.e., with a space defined between the male and female sections and then materials used for making the frame member 4 are injected into the space. Immediately after the injection, the materials are subjected to a molding pressure to be molded thereby to the frame member 4 pasted the blank sheet 3, that is, to obtain the main body. This process has the advantage of manufacturing the main body 1 simply.
With the main body 1 as above described, it is stored until the contents such as washing powders and the like are contained therein. A space for storing the main bodies 1 must be reduced in order to store them efficiently. The main bodies 1 are therefore stacked several bodies high so as to insert a bottom portion of an upper main body, denoted by the character C in FIG. 11, into the opening 2 of the lower main body 1.
After molding of the main body 1, it is cooled to the room temperature. During cooling, the blank sheet 3 and the frame member 4 shrink slightly as their respective temperatures approach room temperature. However, they have different shrinkage coefficients, so that the four side surfaces of the main body 1 become outwardly slightly curved. When the main bodies 1 are stacked, peripheral portions of the curved surfaces of the upper main body 1 come in contact with peripheral edges of the opening 2 of the lower main body 1 to thereby prevent the upper main body 1 from further deeply inserting into the lower. Specifically, the upper main body is unstably hung on the peripheral edges of the opening 2 of the lower. Thus, the main bodies 1 cannot be stacked very highly, usually not more than ten to fifteen bodies high.